[Libguestfs] [PATCH v3] windows: delay installation of qemu-ga MSI

[Richard W.M. Jones]

On Thu, Mar 05, 2020 at 12:47:58PM +0100, Tomáš Golembiovský wrote:
> On Thu, Mar 05, 2020 at 08:49:04AM +0000, Richard W.M. Jones wrote:
> > On Tue, Mar 03, 2020 at 03:45:49PM +0100, Tomáš Golembiovský wrote:
> > > Instead of running firstboot script during early boot schedule a task
> > > delayed for 2 minutes.
> > > 
> > > During the first boot, after virt-v2v conversion, Windows installs the
> > > drivers injected by virt-v2v. When this installation is finished
> > > Windows enforces some kind of internal reboot. This unfortunately
> > > terminates any running firstboot scripts thus killing the installation
> > > of qemu-ga MSI.
> > > 
> > > This is just a best-effort mitigation. It can still happen (e.g. with
> > > slow disk drives) that the drivers are not yet installed when the
> > > delayed installation starts. On the other hand we cannot delay it too
> > > much otherwise we risk that the users logs in and will be doing some
> > > work when the MSI installation starts. After MSI installation finishes
> > > the VM needs to be rebooted which would be annoying if that would happen
> > > under users hands. Although this is not a best fix (that may come later
> > > as it is more complex, e.g. introducing waiting mechanism), the delay as
> > > it is defined works in most cases. And it dramaticaly improves the
> > > situations -- originaly I experienced more than 90% failure rate.
> > > 
> > > Signed-off-by: Tomáš Golembiovský <tgolembi at redhat.com>
> > > ---
> > >  common                 |  2 +-
> > >  v2v/convert_windows.ml | 12 ++++--------
> > >  2 files changed, 5 insertions(+), 9 deletions(-)
> > > 
> > > diff --git a/common b/common
> > > index ea10827b..5371257c 160000
> > > --- a/common
> > > +++ b/common
> > > @@ -1 +1 @@
> > > -Subproject commit ea10827b4cfb3cfe5f782421c01d2902e5f73f90
> > > +Subproject commit 5371257c3cf27fb09d5f2e31ba378b0e6ccf5df6
> > > diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
> > > index 0fda1d4e..bed5989a 100644
> > > --- a/v2v/convert_windows.ml
> > > +++ b/v2v/convert_windows.ml
> > > @@ -429,14 +429,10 @@ popd
> > >     List.iter (
> > >       fun msi_path ->
> > >         let fb_script = "\
> > > -echo Installing qemu-ga from " ^ msi_path ^ "
> > > -\"\\" ^ msi_path ^ "\" /norestart /qn /l+*vx \"%~dpn0.log\"
> > > -set elvl=!errorlevel!
> > > -echo Done installing qemu-ga error_level=!elvl!
> > > -if !elvl! == 0 (
> > > -  echo Restarting Windows...
> > > -  shutdown /r /f /c \"rebooted by firstboot script\"
> > > -)
> > > +echo Removing any previously scheduled qemu-ga installation
> > > +schtasks.exe /Delete /TN Firstboot-qemu-ga /F
> > > +echo Scheduling delayed installation of qemu-ga from " ^ msi_path ^ "
> > > +powershell.exe -command \"$d = (get-date).AddSeconds(120); schtasks.exe /Create /SC ONCE /ST $d.ToString('HH:mm') /SD $d.ToString('MM/dd/yyyy') /RU SYSTEM /TN Firstboot-qemu-ga /TR \\\"C:\\" ^ msi_path ^ " /forcerestart /qn /l+*vx C:\\" ^ msi_path ^ ".log\\\"\"
> > >  " in
> > >        Firstboot.add_firstboot_script g inspect.i_root
> > >          ("install " ^ msi_path) fb_script;
> > 
> > It could be easier to follow if you use sprintf here, something like:
> > 
> > let fb_script = sprintf "\
> > echo Removing any previously scheduled qemu-ga installation
> > schtasks.exe /Delete /TN Firstboot-qemu-ga /F
> > echo Scheduling delayed installation of qemu-ga from %s
> > powershell.exe -command \"$d = (get-date).AddSeconds(120); schtasks.exe /Create /SC ONCE /ST $d.ToString('HH:mm') /SD $d.ToString('MM/dd/yyyy') /RU SYSTEM /TN Firstboot-qemu-ga /TR \\\"C:\\%s /forcerestart /qn /l+*vx C:\\%s.log\\\"\"
> >   msi_path msi_path msi_path in
> 
> Ok, I can change that.
> 
> > 
> > The other possible problem is this seems to install a firstboot script
> > for every element of the list qemu_ga_files.  How long is this list?
> 
> At the moment it is just one. Until something changes in virtio-win ISO
> or in our internal logic (like in virtio_iso_path_matches_qemu_ga()) it
> will always be one.
> 
> > 
> > Do filenames on this list need some kind of quoting?  The filenames
> > don't, but they seem to contain a path that comes from the virtio-win
> > ISO.
> 
> Those are really just file names without path. See 
> https://github.com/libguestfs/virt-v2v/blob/master/v2v/windows_virtio.ml#L339

I'll ACK this, but I think using sprintf is better.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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